Who are the "black Irish"?

Many years ago my grandmother told me that her grandfather's ethnicity was "black Irish." Recently I've heard three different explanations concerning the origin of the term:

(1) It refers to a mixture of Irish and Spanish blood dating from the time of the Spanish Armada, when many shipwrecked Spanish sailors were washed up on the Irish coastline and wound up staying.

(2) It refers to a mixture of Irish and eastern European blood.

(3) It refers to a mixture of Irish and Italian blood from the time of the Roman Empire.

No books have been written on the subject, and no entry is to be found in either the Encyclopedia Britannica or the Oxford English Dictionary. So naturally one turns to you.

— Christian Ard, San Francisco

Cecil replies:

Naturally. One saves the big guns for last.

It seemed to me a reasonable first step would be to see if they'd heard of the black Irish in Ireland. Having inquired of several Irish natives, either in person or via the Internet, I'd say the answer is no — the black Irish are strictly an American hangup.

People talk about the black Irish as though it were a mythical race on a par with the lost tribes of Israel. But in fact all they mean (usually) is that somebody named McNulty has dark, and in the classic case black, hair. Even if we make the dubious assumption that dark hair genes were completely absent in the original Gaels, it seems likely that the incidence of dark-haired folk in a nation whose population only slightly exceeds that of the city of Los Angeles can be accounted for strictly by routine mixing due to immigration, trade contact, and so on. But you can see how exciting an explanation that makes. So people have come up with all kinds of fanciful tales instead.

The wildest notion is that black hair is evidence of Spaniards marooned in Ireland following the wreck of the Armada. But as we discussed in this column long ago, the number of shipwrecked Spanish sailors who remained in Ireland for any length of time was trivial.

I've also heard it said the black Irish were the first settlers of Ireland — maybe the Phoenicians. The red Irish, meanwhile, were descendants of the Normans, and the blond Irish are descended from the Vikings. One of many drawbacks to this theory is that it seems to leave the Gaels completely out of the picture.

A more plausible but still essentially unprovable version of this idea is that black hair is a vestige of an indigenous population of short dark-haired types overrun by the fair-haired Gaels. Supposedly there are more black Irish in the western part of the country, which fewer Gaelic invaders reached. There is archaeological and, I'm told, linguistic evidence of pre-Gaelic settlement, but how it was concluded that they were short and black-haired I don't know.

We could go on like this for another couple pages, but why? While the Irish in me finds it entertaining, the Yankee thinks it's a damfool waste of time.